you have to play around the wide mode settings. its either deep down in the TV settings menu or in advanced options in the channel menu(press the key opposite to the home key in the remote)>advanced options>wide mode.
hope this helps.

I have similar problems with the att uverse STB. When I changed the screen size to "wide" on the STB, the aspect ration seems to be off and the channel programming menu is not completely visible on the screen. Please help!!!